A Link-Level protocol used to facilitate reliable point-to-point transmission of a data packet.
Note: A subset of HDLC, known as "LAP-B,"is the Layer-two protocol for ITU-T Recommendation X.25.

A computer programming language that is primarily designed for, and syntactically oriented to, particular classes of problems and that is essentially independent of the structure of a specific computer or class of computers; for example, Ada®, COBOL, Fortran, Pascal. Synonym high-order language.

Synonym high-level language.

A filter that passes frequencies above a given frequency and attenuates all others.

Equipment that (a) has the performance characteristics required for use in trunks or links, (b) is designed primarily for use in global and tactical systems, and (c) sufficiently withstands electromagnetic interference when operating in a variety of network or point-to-point circuits.
Note: Requirements for global and tactical high-performance equipment may differ.

A call identified as receiving emergency service treatment, which has been marked as requiring special treatment by the emergency service administration. The call has an associated CESID and transfer numbers. [T1.628-1993]

A group of trunks for which an alternate route has been provided to absorb the relatively high rate of overflow traffic.

Deprecated term name. See facility grounding system.

1. A digital serial-coded bit stream with time slots allotted to each call on a sequential basis.
2. A common path or a set of parallel paths over which signals from more than one channel pass with separation achieved by time division.

Noise in the audio frequency range, having subjective characteristics analogous to prolonged sibilant sounds.
Note: Noise in which there are no pronounced low-frequency components may be considered as hiss.